Method for saving energy in paper production

Abstract

The present invention is in the field of paper production, more in particular it relates to the process of wood pulping. It provides useful biological methods and compounds for reducing the energy requirements of the production of wood pulp. It describes a method for reducing the energy requirement of a thermo-mechanical pulping (TMP) process wherein cellulose fibers are recovered from a biomass comprising lignocellulosic material, wherein the lignocellulosic material is treated with a CotA laccase before recovering the cellulose from the lignocellulosic material.

The invention claimed is: 
     
       1. A method for recovering cellulose from a biomass comprising lignocellulosic material, the method comprising:
 contacting the biomass with a CotA laccase prior to heating the biomass to a temperature above 100 degrees Celsius; 
 heating the biomass to a temperature above 100 degrees Celsius; 
 subjecting the heated biomass to mechanical defibration; and 
 wherein the CotA laccase has a primary amino acid structure having at least 99% sequence identity to the sequence of COT1 (SEQ ID NO:1). 
 
     
     
       2. The method according to  claim 1 , wherein the lignocellulosic material comprises wood. 
     
     
       3. The method according to  claim 2 , wherein the wood is a wood chip. 
     
     
       4. The method according to  claim 2 , wherein the wood is a destructured wood chip. 
     
     
       5. The method according to  claim 1 , further comprising treating the biomass comprising the lignocellulosic materials with a chemical composition before the biomass is defibrated. 
     
     
       6. The method according to  claim 5 , wherein the chemical is able to degrade lignin. 
     
     
       7. The method according to  claim 2 , wherein the wood has a moisture content of at least 20% and is preheated to a temperature below 100 degrees Celsius before treating the wood with CotA laccase. 
     
     
       8. The method according to  claim 7 , wherein the wood is preheated to a temperature below the inactivation temperature of the CotA laccase. 
     
     
       9. The method according to  claim 7 , wherein the treatment with CotA laccase is performed after a low energy mechanical treatment step. 
     
     
       10. The method according to  claim 7 , further comprising an impregnation step wherein the biomass comprising lignocellulosic material is contacted with a chemical composition or an enzyme before or after the biomass is contacted with the CotA laccase. 
     
     
       11. The method according to  claim 1 , wherein the biomass comprising a lignocellulosic material is reject pulp. 
     
     
       12. A method for recovering cellulose from a biomass comprising lignocellulosic material, the method comprising:
 contacting the biomass with a CotA laccase prior to heating the biomass to a temperature above 100 degrees Celsius; 
 heating the biomass to a temperature above 100 degrees Celsius; and 
 subjecting the heated biomass to mechanical defibration; 
 wherein the CotA laccase has a primary amino acid structure having at least 98% sequence identity to the sequence of COT1 (SEQ ID NO: 1). 
 
     
     
       13. A method for recovering cellulose from a biomass comprising lignocellulosic material, the method comprising:
 contacting the biomass with a CotA laccase prior to heating the biomass to a temperature above 100 degrees Celsius; 
 heating the biomass to a temperature above 100 degrees Celsius; and 
 subjecting the heated biomass to mechanical defibration; 
 wherein CotA is COT1 (SEQ ID NO:1) or COT2 (SEQ ID NO:2). 
 
     
     
       14. A method for recovering cellulose from a biomass comprising lignocellulosic material, the method comprising:
 contacting the biomass with a CotA laccase prior to heating the biomass to a temperature above 100 degrees Celsius; 
 heating the biomass to a temperature above 100 degrees Celsius; and 
 subjecting the heated biomass to mechanical defibration; 
 wherein the CotA laccase has a primary amino acid structure having at least 99% sequence identity to the sequence of COT2 (SEQ ID NO:2).